• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1993년도 하계학술대회 논문집 B
• /
• pp.578-580
• /
• 1993

The impulse impedence of grounding system must be accurately evaluated for a safe grounding design. However, a calculation nettled of the impulse impendence of a horizontal grounding electrode has not been established yet. This paper presents a method to compute the impulse impedance of a rod type grounding electrode and deals with the analysis of the transient characteristics on the electrodes.

• 한국지진공학회:학술대회논문집
• /
• 한국지진공학회 1999년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall
• /
• pp.265-272
• /
• 1999

there is no earthquake resistant design code for the unreinforced masonary(URM) buildings in Korea. But it does not mean that all URM buldings in Korea is safe under the possible extent of an earthquake. The purpose of this study is in the inelastic analysis of unreinforced masonary walls with many different types of openings and carry out their ductilities an strengths, response modification factor of each wall has been compared and the most appropriate response modification factor for URM building in Korea has been proposed.

• 한국지리정보학회지
• /
• 제15권4호
• /
• pp.78-89
• /
• 2012

본 연구는 범죄발생 자료를 이용하여 시계열적으로 공간적 분포특성을 파악하고, 범죄발생 장소의 공간적 환경 특성을 분석함으로써 도시공간의 물리적인 환경 개선을 통한 범죄예방 가능성을 타진해 보는데 목적이 있다. 사례도시의 범죄자료는 지리정보시스템을 이용하여 공간데이터로 변환하여 사용하였다. 범죄발생의 공간분석을 통해 향후 범죄발생 지역의 변화를 확인하고, 환경설계나 도시계획으로 범죄를 예방할 수 있는 방안을 제시하였다. 구체적으로 2008년과 2011년 2개년 동안 범죄발생의 공간적 분포 패턴을 분석해 본 결과 국지적인 핫스팟의 이동이 발견되었다. 또한 상업지역을 중심으로 도로를 따라 선형으로 범죄 다발지역이 형성되고, 블록의 내부보다 도로변의 환경개선과 범죄예방 전략이 중요함을 알 수 있었다. 이외에도 사례지역을 위험지역과 안전지역으로 분류하고, 안전한 도시 만들기를 위해 도시계획 관점에서 접근하는 것도 필요함을 지적하였다. 연구의 결과는 도시의 물리적 환경개선으로 근본적인 범죄예방을 도모하고 그 결과로서 안전도시를 만드는데 기여할 것이다.

• 한국항해학회지
• /
• 제24권5호
• /
• pp.423-433
• /
• 2000

Nowadays LNG has been beginning to take the place of petroleum as fuel all over the world and VLCC of LNG will take the same sea routes that had been used by VLCC tankers of petroleum in the last part of the 20th century. The transportation of LNG by a VLCC include more dangerous nature of sea peril than that of petroleum. We already know the dimensions of a disaster a LNG tanker could bring about in the case of the LNG tanker, Yuyo-Maru No. 10 in the Tokyo Bay of Japan in 1974. From the point of safety when we construct a LNG base or LNG pier in the base, the appropriate government authority and constructing company had better take sea pilots or some ships handling experts to participate in a prior consultation of the design of the project. A G/T 100,000 ton LNG base and pier were completed in November of 1996 in Inchon harbour in Korea and VLCC of LNG of G/T 100,000 ton class have been entering into the base ever since. This study was started and completed In comply with the requisition of the Sea Pilot Association of Inchon harbour in advance of the opening of the LNG base. As the entrance and exit channels leading to Inchon harbour were constructed in the years of 1930s, it was one of the most pressing works for Inchon sea pilots in 1996 to certify the method of safe passing maneuvering of a G/T 100,000 ton of LNG tanker through the Pudo narrow channel prior to commencing actual piloting of the VLCC of LNG. The authors made some mathematical models computing maneuvering of a vessel changing her course with her control surface through a narrow channel and computed maneuvering of a G/T 100,000 ton of LNG tanker and also made maneuvering simulations of the vessel by a desk-top simulator. The results of computations and simulations are well coincided with each other in qualitative aspects to assure safe passing of the VLCC of LNG.

• 전기학회논문지
• /
• 제63권8호
• /
• pp.1064-1069
• /
• 2014

The railway signalling system plays an essential role in the headway and routing control for a safe and efficient train operation. The reliable and safe operation of the system is very important because the failure of the railway signalling system can lead to the collision, derailment, or unexpected stop of a train. So far, the conventional wayside signal mode (ATS: Automatic Train Stop) has been generally used as the railway signalling system. However, this system is highly linked to a risk of major accidents resulted from human mistakes such as missing a signal or careless control of train speed. Accordingly, the onboard signal mode (ATC: Automatic Train Control) as an alternative of ATS has been recently introduced and applied to transmit effectively the information on speed control of a train by using computers and communication equipment. In the process of replacing the obsolete signal system, it is necessary to switch over the system while providing passengers with normal services. Therefore, the integration of a railway signaling system compatible for both ATS and ATC and its interface is discussed in this study. In particular, the implementation scenario required for operation planning of the integrated system was designed, and the results as well as effects of its applicability test were also presented.

• 한국항해항만학회지
• /
• 제43권6호
• /
• pp.361-368
• /
• 2019

항로표지는 등광, 형상, 색채, 음향, 전파를 이용하여 선박의 안전항해를 돕기 위한 인위적인 시설을 의미한다. 국제항로표지협회에서는 이러한 항로표지의 설계, 배치, 관리 등을 위해 전문가 그룹에 대한 교육과정을 개발하여 운영 중에 있으며, 해기교육기관에서는 항해사들을 위한 선박조종향상교육 및 ECDIS 교육과정을 통하여 안전항해를 위한 다양한 교육을 운영하고 있다. 이에 더불어, 다양한 지형적, 환경적, 해상교통환경 등에 따른 항로표지의 오인으로 인한 해양사고를 예방하기 위해 항로표지 시뮬레이션 시스템을 활용한 교육이 필요하다. 본 연구에서는 기존의 선박조종시뮬레이터와 항로표지 시뮬레이터를 활용하여 다양한 환경에서 항로표지에 대한 정확한 이해과 활용을 위한 교육모듈 개발을 통해, 기존의 이론적인 관점에서의 교육을 보완하고 실무적인 활용도를 높여 교육효과 향상방안을 제시하였다.

• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 2000년도 Proceeding of CIN-KIN Joint Symposium 2000 on M.E.T. Under STCW 78/95 and SINO-KOREA MARITIME CONTACT IN MID-CENTURIES
• /
• pp.115-155
• /
• 2000

Nawadays LNG has been beginning to take the place of petroleum as fuel all over the world and VLCC tankers of LNG will take the same sea routes that had been used by VLCC tankers of petroleum in the last pat of he 20th century. The transportation of LNG by a VLCC include more dangerous nature of sea peril than that of petroleum. We already know the dimensions of a disaster a LNG tanker could bring about in the case of the LNG tanker, Yuyo-Maru No. 10 in the Tokyo Bay of Japan in 1974. From the point of safety when we construct a LNG base or LNG pier in the base, the appropriate government authority and constructing company had better take sea pilots or some ships handling experts to participate in a prior consultation of the design of the project. A G/T 100,000 ton LNG base and pier were completed in November of 1996 in Inchon harbour in Korea and LNG VLCC tankers of G/T 100,000 ton class have been entering into the base ever since. This study was started and completed to comply with the requisition of the Sea Pilot Association of Inchon harbour in advance of the opening of the LNG base. As the entrance and exit channels leading to Inchon harbour were constructed in the years of 1930s, it was one of the most pressing works for Inchon sear pilots in 1996 to certify the method of safe passing maneuvering of a G/T 100,000 ton LNG tanker through the Pudo narrow channel prior to commercing actual piloting of the LNG VLCC tanker. The author made some mathematical models computing maneuvering of a vessel changing her course with her control surface through a narrow channel and computed maneuvering of a G/T 100,000 ton LNG tanker and also made maneuvering simulations of the vessel by a desk-top simulator. The results of computations and simulations are well coincided with each other in qualitative aspects to assure safe passing of the LNG VLCC.

• 제어로봇시스템학회논문지
• /
• 제18권6호
• /
• pp.584-593
• /
• 2012

This paper introduces an AVP (Automated Valet Parking) system which applies an autonomous driving concept into the current PAS (Parking Assistant System). The present commercial PAS technology is limited into vehicle. It means vehicle only senses and controls by and for itself to assist the parking. Therefore, the present PAS is restricted to simple parking events. But AVP includes wider parking events and planning because it uses infra-sensor network as well as vehicle sensor. For the realization of AVP, the commercial steering system of a compact vehicle was modified into steer-by-wire structure and various sensors like LRF (Long Range Finder) and camera were installed in a parking area. And local & global server decides where and when the vehicle can go and park in the testing area after recognized the status of environment and vehicle from those sensors. GPS solution was used to validate the AVP performance. More various parking situations, vehicles and obstacles will be considered in the next research stages based on these results. And we expect this AVP solution with more intelligent vehicles can be applied in a big parking lot like a market, an amusement park, etc.

• Archives of Plastic Surgery
• /
• 제44권4호
• /
• pp.332-336
• /
• 2017

Background Little is known concerning hair diameter variation within the safe donor area for hair transplantation surgery. Thicker or thinner hair may be needed, depending on the recipient area, hairline design, and the purpose of surgery. Methods Twenty-seven patients (7 men and 20 women; mean age, 28 years; range, 20-47 years) were included in this study. The midoccipital point was used as the reference point on the horizontal plane at the upper border of the helical rim. The target area width was 15 cm (7.5 cm to the right and left of the reference point) and the height was 8 cm (2 cm above and 6 cm below the reference point). The study area was divided horizontally into 3 5-cm sections (A, B, C) and vertically into 4 2-cm sections (1-4), creating a total of 12 zones. Ten anagen hairs were randomly obtained from each zone and their diameters were measured. Results Hair diameter in the 4 vertical sections varied significantly, gradually decreasing from sections 1 (superior) to 4 (inferior) in all 3 horizontal sections (A, B, and C). Conclusions Our results suggest that sections 1 and 2 of the occipital safe donor area would be useful for obtaining thicker hair, such as in procedures to treat male- and female-pattern hair loss, whereas hair from zones 3 and 4 could be useful for transplantation surgery requiring thinner hair, such as eyebrows, eyelashes, and female hairline correction. Our results may be clinically valuable for planning hair transplant surgery and choosing the optimal donor region.

• 한국항해학회지
• /
• 제10권2호
• /
• pp.83-96
• /
• 1986

In the restricted sea way such as fair way in harbor, narrow channel etc, the safe ship-handling is a very important problem, which is greatly related with turning ability of ships. It is of great importance that ship-handlers can grasp the position of pivoting point varying with time increase at any moment for relevant steering activities. Mean while, in advanced ship-building countries they study and investigated pivoting point related with turning characteristics, hut their main interest lies in ship design, not in safe ship controlling and maneuvering. In this regards it is the purpose of this paper to provide ship-handlers better under standing of pivoting point location together with turning characteristics and then to help them in safe ship-handling by presenting fact that pivoting points vary according to configuration of ships. The author calculated the variation of pivoting point as per time increase for various type of vessels, based on the hydrodynamic derivatives obtained at test of Davidson Laboratory of Stevens Institutes of Technology , New Jersey, U.S.A. The results were classified and investigated according to the magnitude of block coefficient , length-beam ratio, length-draft ratio, rudder area ratio ete, and undermentioned results were obtained. (1) The trajectory of pivoting point due to variation of rudder angle are all the same at any time, though the magenitude of turning circle are changed variously. (2) The moving of pivoting point is affected by the magnitude of block coefficient, length-beam ratio, length-draft ratio, however the effect by rudder area ratio might be disregarded. (3) In controlling and maneuvering of vessels in harbor, ship-handlers might regard that the pivoting point would be placed on 0.2~0.3L forward from center of gravity at initial stage. (4) The pivoting point of VLCC or container feeder vessels which have block coefficient more than 0.8 and length-beam ratio less than 6.5 are located on or over bow in the steady turning. (5) When a vessel intends to avoid some floating obstruction such as buoy forward around her eourse, the ship-handler might consider that the pivoting point would be close by bow in ballast condition and cloase by center of gravity in full-loaded condition.